Maize/Soybean Relay Strip Intercropping Reduces the Occurrence of Fusarium Root Rot and Changes the Diversity of the Pathogenic Fusarium Species

Abstract

Fusarium species are the most detrimental pathogens of soybean root rot worldwide, causing large loss in soybean production. Maize/soybean relay strip intercropping has significant advantages on the increase of crop yields and efficient use of agricultural resources, but its effects on the occurrence and pathogen population of soybean root rot are rarely known. In this study, root rot was investigated in the fields of the continuous maize/soybean strip relay intercropping and soybean monoculture. Fusarium species were isolated from diseased soybean roots and identified based on sequence analysis of translation elongation factor 1α (EF-1α) and RNA polymerase II second largest subunit (RPB2), and the diversity and pathogenicity of these species were also analyzed. Our results showed that intercropping significantly decreased soybean root rot over monoculture. A more diverse Fusarium population including Fusarium solani species complex (FSSC), F. incarnatum-equiseti species complex (FIESC), F. oxysporum, F. fujikuroi, F. proliferatum and F. verticillioides, F. graminearum and F. asiaticum was identified from intercropping while FSSC, FIESC, F. oxysporum, F. commune, F. asiaticum and F. meridionale were found from monoculture. All Fusarium species caused soybean root infection but exhibited distinct aggressiveness. The most aggressive F. oxysporum was more frequently isolated in monoculture than intercropping. FSSC and FIESC were the dominant species complex and differed in their aggressiveness. Additionally, F. fujikuroi, F. proliferatum and F. verticillioides were specifically identified from intercropping with weak or middle aggressiveness. Except for F. graminearum, F. meridionale and F. asiaticum were firstly reported to cause soybean root rot in China. This study indicates maize/soybean relay strip intercropping can reduce soybean root rot, change the diversity and aggressiveness of Fusarium species, which provides an important reference for effective management of this disease.

Changing light promotes isoflavone biosynthesis in soybean pods and enhances their resistance to mildew infection

“…As a serious plant disease, field mildew (FM) is caused by the infection of Fusarium verticillioides during the wet season before soybean harvest and results in significant soybean yield losses (Liu et al, 2017). Our multiyear survey of disease dynamics confirmed the FM rate of soybean plants growing under the MSI system was significantly lower than that in soybean plants growing alone (Chang et al, 2020). From our field survey in recent years, the mildew rate of soybean pods harvested from the maize‐soybean relay strip IT system was less than a quarter of sole cropping soybean pod (Supplemental Figure S1).…”

Symptoms and pathogens diversity of Corn Fusarium sheath rot in Sichuan Province, China

“…Fusarium meridonale is a member of the FGSC that is well-known to cause FHB in wheat and barley worldwide 41 . In addition, F. meridionale was also recently reported as pathogen in root rot on soybean under monoculture and ear rot on maize 42 , 43 . Moreover, F. asiaticum has been reported as a major and dominant causal agent of FHB on wheat and barley in China 44 – 46 and was also detected as a pathogen causing Gibberella ear rot of maize and seedborne diseases of soybean 47 , 48 .…”

Sugarcane-Legume Intercropping Can Enrich the Soil Microbiome and Plant Growth

“…Besides this, Khippal et al (2016) also observed that other crops, such as chickpea and lentils could be effectively intercropped with sugarcane to improve the cane quality and soil physical condition for sustainable agricultural crop production. Recent reports also indicate that maize intercropping improves nutrition (Ridaura et al, 2021), reduces disease (Chang et al, 2020), and enhances the yield of the crops (Crusciol et al, 2020).…”